This invention relates to 1-benzopyransulfonamides, 1-benzothiopyransulfonamides, 1-benzoxepinsulfonamides and 1-benzothiepinsulfonamides which are useful as plant growth regulants and in particular as herbicides.
Netherlands Pat. No. 121,788, published Sept. 15, 1966, discloses the preparation of compounds of the following Formula and their use as general or selective herbicides: ##STR1## wherein
R.sub.1 and R.sub.2 may independently be alkyl of 1-4 carbon atoms; and
R.sub.3 and R.sub.4 may independently be hydrogen, chlorine or alkyl of 1-4 carbon atoms.
U.S. Pat. No. 3,637,366 discloses compounds having the formula: ##STR2## wherein
R.sub.1 is hydrogen or lower saturated aliphatic acyl and
R.sub.2 is hydrogen, 2-pyrimidinyl, pyridyl, amidino, acetyl or carbamoyl.
The disclosed compounds are said to provide control of crabgrass, cress, endive, clover and Poa annua.
French Pat. No. 1,468,747 discloses the following para-substituted phenylsulfonamides as being useful as antidiabetic agents: ##STR3## wherein
R=H, halogen, CF.sub.3 or alkyl.
Logemann et al., Chem. Ab., 53, 18052g (1959), disclose a number of sulfonamides, including uracil derivatives and those having the formula: ##STR4## wherein
R is butyl, phenyl or ##STR5## and
R.sub.1 is hydrogen or methyl.
When tested for hypoglycemic effect in rats (oral doses of 25 mg/100 g), the compounds in which R is butyl and phenyl were most potent. The others were of low potency or inactive.
Wojciechowski, J. Acta. Polon. Pharm. 19, p. 121-5 (1962) [Chem. Ab., 59 1633 e] describes the synthesis of N-[(2,6-dimethoxypyrimidin-4-yl)aminocarbonyl]-4-methylbenzenesulfonamide: ##STR6##
U.S. Pat. No. 4,127,405 teaches compounds which are useful for controlling weeds in wheat having the formula ##STR7## wherein ##STR8##
R.sub.3 and R.sub.6 are independently hydrogen, fluorine, chlorine, bromine, iodine, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, trifluoromethyl, cyano, CH.sub.3 S(O).sub.n -- or CH.sub.3 CH.sub.2 S(O).sub.n --;
R.sub.4 is hydrogen, fluorine, chlorine, bromine or methyl;
R.sub.5 is hydrogen, fluorine, chlorine, bromine, methyl or methoxy;
R.sub.7 is hydrogen, fluorine, chlorine, bromine, alkyl of 1-2 carbon atoms or alkoxy of 1-2 carbon atom;
R.sub.8 is hydrogen, methyl, chlorine or bromine;
R.sub.9 and R.sub.10 are independently hydrogen, methyl, chlorine or bromine;
W and Q are independently oxygen or sulfur;
n is 0, 1 or 2;
X is hydrogen, chlorine, bromine, methyl, ethyl, alkoxy of 1-3 carbon atoms, trifluoromethyl, CH.sub.3 S-- or CH.sub.3 OCH.sub.2 --; and
Z is methyl or methoxy;
or their agriculturally suitable salts; provided that:
(a) when R.sub.5 is other than hydrogen, at least one of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 is other than hydrogen and at least two of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be hydrogen;
(b) when R.sub.5 is hydrogen and all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 are other than hydrogen, then all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be either chlorine or methyl; and
(c) when R.sub.3 and R.sub.7 are both hydrogen, at least one of R.sub.4, R.sub.5 or R.sub.6 must be hydrogen.
In addition, Unexamined European patent application No. 35,893 teaches o-alkylsulfonylbenzenesulfonylureas which are useful as herbicides.
In U.S. Pat. No. 4,391,627, there is a disclosure of herbicidal benzo[b]thiophene and benzofuransulfonylureas in which the sulfonylureido group is bonded to the heterocyclic ring.
South African patent application No. 835165 filed by Ciba-Geigy (Swiss Priority 7/16/82) discloses herbicidal sulfonylureas of the general structure shown below: ##STR9## wherein
A is an unsubstituted or substituted bridge of 3 or 4 atoms which contains 1 or 2 oxygen, sulfur or nitrogen atoms and, together with the linking carbon atom, forms a non-aromatic 5- or 6-membered heterocyclic ring system, with the proviso that two oxygen atoms are separated by at least one carbon atom and that oxygen and sulfur atoms are only linked to each other if the sulfur atom takes the form of the --SO-- or SO.sub.2 -- group.
South African patent application No. 837434 discloses herbicidal sulfonamides of formula ##STR10## where ##STR11##
R.sub.2 is halogen, C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 haloalkyl, C.sub.1 -C.sub.3 alkoxy, C.sub.1 -C.sub.3 haloalkoxy, amino, C.sub.1 -C.sub.3 alkylamino, di(C.sub.1 -C.sub.3 alkyl)amino, C.sub.3 -C.sub.6 cycloalkyl or C.sub.2 -C.sub.6 alkoxyalkyl.
EP-A-79,683, published May 25, 1983, discloses herbicidal sulfonamides of formula ##STR12## where
J is various benzofuran, benzothiophene, 1-benzopyran, 1-benzothiopyran, 1-benzoxepin and 1-benzothiepin moieties;
X is H, CH.sub.3, OCH.sub.3 or Cl;
Y is CH.sub.3, OCH.sub.3, OCH.sub.2 CH.sub.3, CH.sub.2 OCH.sub.3, CH.sub.2 CH.sub.3, NH.sub.2, NHCH.sub.3 or N(CH.sub.3).sub.2 ; and
Z is CH or N.
Undesired vegetation can cause substantial damage to useful crops, especially agricultural products that satisfy man's basic food and fiber needs, such as cotton, rice, corn, wheat, soybean and the like. Although a wide variety of materials are available which can be used for killing or inhibiting (controlling) the growth of undesired vegetation the need exists for still more effective herbicides that destroy or control weeds without causing significant damage to useful crops.